Transient behaviour in a BWR with Hafnium Cladding: Feasibility study of using BWRs as Higher Actinide Burners at the Example of Ringhals I
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Transmutation of transuranic elements is of interest to lower storage unit cost and long-term radiotoxicity. To make use of existing infrastructure, the deployment of Boiling Water Reactors (BWRs) with hafnium cladding and Mixed Oxide (MOX) fuel was proposed, resulting in a hardening of the neutron spectrum. This work tests varying spatial fuel configurations for maximal burn-up, using Serpent, and study their behaviour in common accident scenarios, simulated by a coupled TRACE/PARCS software suite. To this end, we provide a software solution, which serves to transfer Serpent output of a user defined system in a cross section parameter file, readable by TRACE/PARCS.
The results of the transfer were tested for safety performance and, if they provided satisfactory steady states, subjected to a turbine-trip event without bypass, with or without control rod SCRAM. Building on the works by Suvdantstseg  and Wallenius & Westlen , we chose a Transuranium (TRU) content of 16.48% and a Hafnium-content of 5% with various Higher Actinides (HA) contents and z-axis distributions, intended to either maximize safety performance or minimize void worth and study the results. The chosen fuel loading allows a safe shut-down for both accident scenarios. Sharply rising pressure inside the reactor vessel causes a void collapse. The TRU-content lowers the positive reactivity contribution of increased moderator density, compared to the Uranium Oxide (UOX) baseline. Nonetheless, using a Hf-content of 5% in the cladding and MOX-fuel with 16.48 TRU and 2.06 HA, the void coefficient stays negative during a transitional period of the shutdown, lasting for approximately 200 seconds, before before changing it’s sign.
Place, publisher, year, edition, pages
2011. , 93 p.
Trita-FYS, ISSN 0280-316X ; 36
IdentifiersURN: urn:nbn:se:kth:diva-38189OAI: oai:DiVA.org:kth-38189DiVA: diva2:436206
Subject / course
Master of Science - Nuclear Energy Engineering
UppsokPhysics, Chemistry, Mathematics
Wallenius, Janne, Professor